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Cracked block

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  • Cracked block

    I have a cracked block left side of engine leaking water . May try Blue Devil Block sealer . Any other suggestions other than a new block. I used it last year for a sand hole casting leak in the valve adjusting chamber worked out good so far over 2000 miles on that repair .

  • #2
    Could you describe or show exactly where the crack is?


    • #3
      31Roadster welcome to the VFF,

      For circumstances like that you won't know till you try. We used blue devil technician in a can in the shop for the local used car, lot pass it on headgasket issues and i never really liked it to much. I have had luck with technician in a can K-Seal.. your mileage may vary
      3 ~ Tudor's
      Henry Ford said
      "It's all nuts and bolts"

      Mitch's Auto Service ctr


      • Mitch
        Mitch commented
        Editing a comment
        OH and what about technician in a tube JB weld??
        Like Mike said put up a pic

    • #4
      Hey 31Roadster WELCOME to VFF!
      You wana look waaay far up da road and plan yer route because the brakes are far more of a suggestion than a command!


      • #5
        Will add picture later today. I did use JB weld worked for about 1000 miles. I have removed any remaining JB weld . I'm thinking let the blue devil seep out of the crack for about 100 mile at 100% operating temp to allow expansion and contraction of the crack.then add J B weld over crack as an additional layer of protection.


        • #6
          I'm working on a temporary engine for my 28, and it never leaked a drop. It was only after I stripped the old paint and gave it a new coat that I found 2 freeze cracks in the bottom edge on the left side. I sandblasted the cracks and pressed 24 hour JB Weld into the cracks as well as I could, then before the mix got hard, I lightly wire brushed it to blend in with the rough cast.

          You do not have permission to view this gallery.
          This gallery has 8 photos.


          • Beauford
            Beauford commented
            Editing a comment
            Impressive! I filled all the dents in my gas tank with JB Quicksteel and came out great! I had a small crack in FW housing and used JB on that as well. Is that engine running well?

        • #7
          That is the same Location of my leak . I like blasting it gives JB weld something to bite into . I used a drellel tool the first time and I could not get it rough enough to allow good adhesion .


          • #8
            the blasting makes the surface nice and clean, too, allowing for better adhesion.
            Please whatever you do, do not allow anyone to convince you to weld it, or allow anyone to weld it. No matter what they say. I cannot tell you the number of times customers have had leaks repaired by welding, 'by the best welder around' and the cracks always just get worse. Epoxy repair as Tom shows, and maybe block sealer are good bets. If there is a machine shop nearby that can 'stitch it' using a series of overlapping drilled and tapped plugs that is a superb way to repair.


            • Mickey
              Mickey commented
              Editing a comment
              I was taught by an old Mack truck mechanic how to do that back in 1972. I had a 1954 GCM pickup with about a 6" crack in the right side of the engine water jacket. He called it "lacing". Worked like a champ. Even used the truck to tow my car from Texas to Connecticut on one of my many military transfers. It still wasn't leaking when I sold the truck.

          • #9
            JB Weld High HEAT has held my crack in the front of the water jacket for 3 years.. Like real welding, you have to clean and prep the area and that is 98% of the work...


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